Eternal Witness

When Eternal Witness enters the battlefield, you may return target card from your graveyard to your hand.

Grinding Station

{T}, Sacrifice an artifact: Target player mills three cards.
Whenever an artifact enters the battlefield, you may untap Grinding Station.

Reach
Whenever Six attacks, mill three cards. You may put a land card from among them into your hand.
As long as it's your turn, nonland permanent cards in your graveyard have retrace. (You may cast permanent cards from your graveyard by discarding a land card in addition to paying their other costs.)

Mishra's Bauble

{T}, Sacrifice Mishra's Bauble: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.